The invention relates to a fin for a heat exchanger as claimed in the preamble of Claim 1 and to a heat exchanger having such a fin. The invention also relates to a fin for a heat exchanger as claimed in the preamble of claim 14 and to a method for manufacturing a fin for a heat exchanger.
Heat exchangers are known in which, in order to improve the exchanging performance, the fins are provided in ducts through which fluid flows. Such fins can be embodied, for example, as smooth fins, gill fins or else as web fins. In the first case, owing to the largely laminar flow, only a relatively small improvement in the exchanging performance is achieved but the drop in pressure of the fluid which is brought about by the fins is also relatively small. Web fins exhibit a particularly clear improvement in the exchanging performance for a given structural size, but also give rise to an often undesirably large drop in pressure across the flow duct. Web fins are used, inter alia, in charge air coolers of motor vehicles, predominantly on the charge air side.
DD 0 152 187 describes a strip-shaped tubular installation element for tubular bundle heat exchangers in the field of the petrochemical industry, in which trapezoidal flaps for generating turbulence are provided. The flaps have a variable width in the flow direction, with the flaps being bent out of the strip by an angle of more than 30° about a longer edge of two parallel edges of the trapezoid.
The research report (“Research Memorandum”) number RM A9L29 of the National Advisory Committee for Aeronautics (NACA), Washington, USA, of Feb. 23, 1950, describes a countersunk air inlet for aerofoil whose flow behavior was examined in a velocity range from Mach 0.6 to Mach 1.08.